It is known that a bifunctional compound having a norbornane skeleton exhibits excellent characteristics when used as an adhesive or resin raw material. As the bifunctional compound having a norbornane skeleton, tricyclodecane dicarbaldehyde and pentacyclopentadecane dicarbaldehyde are known, and several production methods have been reported (Patent Document 1).
Patent Documents 2 to 4 describe that tricyclodecane dicarbaldehyde is obtained by hydroformylating dicyclopentadiene in the presence of a rhodium catalyst using a mixed gas of carbon monoxide and hydrogen. Further, Patent Document 5 describes that tricyclodecane dicarbaldehyde or pentacyclopentadecane dicarbaldehyde is obtained by hydroformylating dicyclopentadiene or tricyclopentadiene in the presence of a rhodium catalyst using a mixed gas of carbon monoxide and hydrogen.
The tricyclodecane dicarbaldehyde described in Patent Documents 2 to 5 is a compound in which one norbornane and cyclopentane share a plurality of atoms with each other to form the main skeleton as shown in formula (5) below. Further, the pentacyclopentadecane dicarbaldehyde described in Patent Document 5 is a compound in which two norbornanes and cyclopentane share a plurality of atoms with each other to form the main skeleton as shown in formula (6) or (7) below.

In Patent Document 2, tricyclodecane dicarbaldehyde is produced by hydroformylating dicyclopentadiene under a high-pressure condition of about 20 to 25 MPa. Accordingly, equipments having high pressure resistance are required in industrial practice, and therefore it is hardly a method excellent in economic efficiency.
Patent Documents 3 and 4 relate to a method for the production of tricyclodecane dicarbaldehyde, and it is characterized in that tricyclodecane dicarbaldehyde is produced by hydroformylating dicyclopentadiene using a slight amount of a rhodium catalyst by controlling the concentration of conjugated diene which is a catalyst poison. However, also in these patent documents, a reaction pressure of at least 9 MPa is required in order to achieve a high yield, and therefore it is desired to develop a method for obtaining a bifunctional compound by means of a reaction under lower pressure condition.
Patent Document 5 relates to a method for the production of tricyclodecane dicarbaldehyde or pentacyclopentadecane dicarbaldehyde, wherein: dicyclopentadiene or tricyclopentadiene is hydroformylated using a rhodium compound as a catalyst; an extraction solvent made of a polyhydric alcohol is added to the obtained reaction solution; tricyclodecane dicarbaldehyde or pentacyclopentadecane dicarbaldehyde that is the reaction product is separated into an extraction solvent layer; and a rhodium complex catalyst is separated into a hydrocarbon-based reaction solvent layer. In order to reduce the cost for the catalyst, it is required to circulate and recycle the rhodium complex catalyst, and equipments for that is essential. Therefore, it is hardly an economical method.
Patent Document 2 also describes a method for producing tricyclodecane dimethanol by hydroformylating dicyclopentadiene to provide dialdehyde and subsequent hydrogenation of this dialdehyde.
Patent Document 6 describes a method for producing tricyclodecane dimethanol, wherein: dicyclopentadiene is subjected to a hydroformylation reaction using a catalyst made of rhodium-phosphite in the presence of a solvent and a tertiary amine compound; and the hydroformylation reaction solution is subjected to hydrogen reduction in the presence of a hydrogenation catalyst.
Patent Document 7 describes a method for producing tricyclodecane dimethanol or pentacyclopentadecane dimethanol, wherein: dicyclopentadiene or tricyclopentadiene is hydroformylated using a rhodium compound as a catalyst; an extraction solvent made of a polyhydric alcohol is added to the obtained reaction solution; a rhodium complex catalyst is separated into a hydrocarbon-based reaction solvent layer; tricyclodecane dicarbaldehyde or pentacyclopentadecane dicarbaldehyde that is the reaction product is separated into an extraction solvent layer; and after that, the extraction solvent layer is subjected to hydrogen reduction in the presence of a hydrogenation catalyst.
The tricyclodecane dimethanol described in Patent Documents 2, 6 and 7 is a compound in which one norbornane and cyclopentane share a plurality of atoms with each other to form the main skeleton as shown in formula (8) below. Further, the pentacyclopentadecane dimethanol described in Patent Document 7 is a compound in which two norbornanes and cyclopentane share a plurality of atoms with each other to form the main skeleton as shown in formula (9) or (10) below.

Patent Document 2 relates to a method for producing tricyclodecane dimethanol in which a high-pressure condition of about 20 to 25 MPa is required. Accordingly, equipments having high pressure resistance are required in industrial practice, and therefore it is hardly a method excellent in economic efficiency.
Regarding the method for producing tricyclodecane dimethanol described in Patent Document 6, in order to achieve a high yield in dialdehyde synthesis based on the hydroformylation reaction, a reaction pressure of at least 9 MPa is required, and therefore it is desired to develop a method for obtaining a bifunctional compound by means of a reaction under lower pressure. Further, when the hydroformylation reaction is performed with a concentration of the rhodium catalyst by which the reaction proceeds and then hydrogen reduction is carried out in the presence of a hydrogenation catalyst, a rhodium complex that is a hydroformylation catalyst is reduced, while the hydrogenation catalyst is poisoned by phosphite contained in the hydroformylation reaction solution, resulting in the problem of increase in the cost for the catalyst.
In the method for producing tricyclodecane dimethanol or pentacyclopentadecane dimethanol described in Patent Document 7, in order to reduce the cost for the rhodium catalyst, it is required to recycle the hydrocarbon-based reaction solvent layer containing the rhodium complex catalyst, and equipments for that is required. Therefore, it is hardly an economical method.
Patent Document 8 describes a bifunctional compound having a tetracyclododecane skeleton, but does not describe any method for producing the bifunctional compound. In addition, Patent Document 8 discloses intended use of polyester resin, but only describes cases of using a 2,6-derivative of the bifunctional compound or a 2,7-derivative of the bifunctional compound independently, and the largest amount of the bifunctional compound used is just 5 mol %. Further, the document does not describe intended use of polycarbonate resin.